/*
 * Class: DBManager.java
 * Copyleft (c) -- Coded by Blay.
 *
 * Class for databse communication.
 *
 * RaBot project -- 1.0 BETA Release
**/

import java.sql.Connection;

import java.sql.Statement;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import java.util.Vector;
// import java.util.Enumeration;


class DBManager

{

    private final String driver = "com.mysql.jdbc.Driver"; // JDBC Driver

    private final int MYSQL_DEFAULT_PORT = 3306;



    private String databaseURL = null; // database url

    private int databasePort = -1; // databse port (3306)

    private String databaseName = null; // database name

    private String databaseUser = null;

    private String databasePassword = null;


    // Initialize database port to default MySQL port number
    {
        this.databasePort = MYSQL_DEFAULT_PORT;
    }


    public DBManager(String url, String name, int port, String user, String pass)

    {
        this(url, name, user, pass);
        this.databasePort = port;

    }



    public DBManager(String url, String name, String user, String pass)

    {

        this.databaseName = name;

        this.databaseUser = user;
        this.databasePassword = pass;
        this.databaseURL = "jdbc:mysql://" + url + ":" + this.databasePort + "/" + name;

    }



    /* DisconnectDB: close db connection */

    void DisconnectDB(Statement s)

    {

        try {

            s.close();

        }

        catch (Exception e){}

    }



    /* ConnectDB: return Connection class for given database */

    Connection ConnectDB()

    {

        Connection c = null;

        try {

            Class.forName(driver).newInstance();

            c = DriverManager.getConnection(databaseURL, databaseUser, databasePassword);



            return c;

        }

        catch (Exception e) {

            e.printStackTrace();
            return null;

        }

    }


    /* getPStatement: returns reference to PreparedStatement, taking SQL query as parameter. Returns null on failure */
    PreparedStatement getPStatement(String statement)
    {
        try {
            /*
             * statement example: "SELECT user FROM mdl_mnet_session_set WHERE id = ?"
             * where '?' gets replaced by value. '?' must be the same type as database
             * field type, for ex.: consider id being type INTEGER you'd have to use setInt()
             * to replace '?' with actual value.
             * This statement is only compiled once and then used again with different values.
            **/

            PreparedStatement ps = this.ConnectDB().prepareStatement(statement);

            return ps;
        }
        catch (SQLException sqle) {
            sqle.printStackTrace();
            return null;
        }
    }

    Statement getStatement()
    {
        Statement s = null;
        try {
            s = this.ConnectDB().createStatement();
        }
        catch (SQLException sqle) {
            sqle.printStackTrace();
            s = null;
        }

        return s;
    }

    /* Used for writing records to database */
    void execQuery(String qry)
    {
        try {
            Statement s = this.ConnectDB().createStatement();
            s.executeUpdate(qry);
            s.close();
        }
        catch (SQLException sqle) {
            sqle.printStackTrace();
        }
    }

    void closeStatement(Statement s)
    {
        try {
            s.close();
        }
        catch (SQLException sqle) {
            sqle.printStackTrace();
        }
    }

    void closePStatement(PreparedStatement ps)
    {
        try {
            ps.close();
        }
        catch (SQLException sqle) {
            sqle.printStackTrace();
        }
    }

    void closeRSet(ResultSet rs)
    {
        try {
            rs.close();
        }
        catch (SQLException sqle) {
            sqle.printStackTrace();
        }
    }

    /*
    void closeRSetMData(ResultSetMetaData rsmd)
    {
        try {
            rsmd.close();
        }
        catch (SQLException sqle) {
            sqle.printStackTrace();
        }
    }
    */

}